• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 17
  • 7
  • 2
  • 2
  • Tagged with
  • 34
  • 34
  • 8
  • 7
  • 6
  • 6
  • 6
  • 5
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Advanced Telemetry Tracking System for High Dynamic Targets

Minschwaner, Nathan, Leide, Nelson Paiva Oliveira 10 1900 (has links)
ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / A new advanced 2.4 meter telemetry tracking antenna system allows for successful autotracking of high dynamic targets. The system is designed to work at C, S, and L bands. One of these systems at L/S-band was recently implemented and tested in the field. The testing included tracking aircraft during maneuvers such as rolls, spins, and antenna tower fly-by at high rates of speed. This paper examines test results and some of the features of the new system that allow for continuous tracking.
12

S-Band Transmitter for NAROM Student Rocket

af Sandeberg, Viktor January 2013 (has links)
Norwegian Centre for Space-related Education (NAROM) performs education within subject areas related to space, such as space physics, atmosphere and space technology. This thesis describes the development of a transmitter to be used in NAROM ́s studentrocket. The requirements were that the transmitter should send with FM at 2279,5 MHz with an output of at least 750 milliwatt and with a speed of 512 kbit/s when NRZ coding is used.The transmitter that was designed and tested in this project used an IC that modulated the signal to FM and sent it out on a low frequency. Then the frequency was multiplied by a IC to the correct value, 2279,5 MHz. Experiments showed that the transmitter worked satisfying, but a problem occurred: The frequency multiplier sent out unwanted overtones and the output power was to low. A final theoretical design was made to solve these problems. The final design uses the same modulation components as the tested transmitter, but filters are added and the amplifiers are changed to be able to handle the filters and give out a higher power. The transmitter can be use for other application that need a transmitter with bit-rate of up to 600 kbit/s and frequency range of 2250-2300 MHz without change of filters. If the filters is change the frequency range will be 2250-2550 MHz. / <p>Validerat; 20131025 (global_studentproject_submitter)</p>
13

ISM S-band CubeSat Radio Designed for the PolySat System Board

Francis, Craig Lee 01 May 2016 (has links) (PDF)
Cal Poly’s PolySat CubeSat satellites have begun to conduct more complex and scientifically significant experiments. The large data products generated by these missions demonstrate the necessity for higher data rate communication than currently provided by the PolySat UHF radio. This thesis leverages the proliferation of consumer wireless monolithic transceivers to develop a 250kbps to 2000kbps, 2W CubeSat radio operating within the 2.45GHz Industrial, Scientific, and Medical (ISM) radio band. Estimating a link budget for a realistic CubeSat leads to the conclusion that this system will require a large deployable CubeSat antenna, large earth station satellite dish, and a fine-pointing attitude control system. Noise floor measurements of a CubeSat ground station demonstrate that terrestrial ISM interference can be minimized to below the thermal noise floor by carefully choosing the operating frequency. The radio is specifically designed as a daughter board for the PolySat System Board with a direct interface to the embedded Linux microprocessor. A state-of-the-art ZigBee transceiver evaluation board is measured to confirm its suitability for a CubeSat radio. A schematic is developed, which integrates the transceiver, power amplifier, low noise amplifier, amplifier protection circuitry, switching regulators, and RF power measurement into a single printed circuit board assembly (PCBA). The circuitry is then squeezed into a high-density, 1.4” x 3.3” layout. The PCBA is then manufactured, troubleshot, tuned, and characterized.
14

Translation of L and S Band Tracking Assets to X Band High Dynamic Testing

Winstead, Michael 10 1900 (has links)
ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / Recent Constraints on the use of L and S band spectrum led to the search for additional Frequency Domain Bandwidth augmentation for test range telemetry needs. The ITU (International Telecommunications Union) approved X band region is listed as 7000 MHz to 8500 MHz for telemetry space applications. Bandwidth is available within this domain subject to the WARC (World Administrative Radio Consortium) approvals. This paper describes tests and presents results illustrating methodology that is available, and which can be used for conversion of S-band assets to the X band spectral region.
15

Performance Comparison of Aeronautical Telemetry in S-Band and C-Band

Temple, Kip, Selbrede, Robert 10 1900 (has links)
ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / This paper compares telemetry link performance of the PCM/FM waveform when simultaneously transmitting in two different frequency bands, S-Band and C-Band. A description of the aircraft and ground station is presented followed by flight test results. These results are presented in the form of received signal strength and accumulated bit errors, versus time and link availability, over the flight paths. Conclusions are drawn based upon the presented flight test results.
16

A Modular Approach to Hardened Subminiature Telemetry and Sensor System (HSTSS) Development

Carpenter, Robert E., Schneider, Dennis 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / In the past, typical telemetry systems for munitions and small missiles have often comprised adaptations of monolithic components originally conceived for aircraft or large missile applications. Programs have developed expensive monolithic systems to meet the needs of specific programs, but they often require extensive redesign for use by other potential users. The tri-service HSTSS Integrated Product Team (IPT) determined that a monolithic “one size fits all” approach has technical and fiscal risks. Thus, a modular approach to system development has been adopted. The HSTSS IPT is flight qualifying commercial microelectronic products designed for environments similar to that of munition interiors, and is developing microelectronic components required to complete a subminiature system. HSTSS components can then be integrated to support the form factor and measurement needs of any given user. In addition to offering a flexible system to the user, the HSTSS lends itself to upgradability (modernization through spares).
17

DESIGN OF AN INSTRUMENT FOR SOIL MOISTURE AND ABOVE GROUND BIOMASS REMOTE SENSING USING SIGNALS OF OPPORTUNITY

Benjamin R Nold (7043030) 15 August 2019 (has links)
Measurements of soil moisture are a crucial component for understanding the global water and carbon cycle, weather forecasting, climate models, drought prediction, and agriculture production. Active and passive microwave radar instruments are currently in use for remote sensing of soil moisture. Signals of Opportunity (SoOp) based remote sensing has recently emerged as a complementary method for soil moisture remote sensing. SoOp reuses general digital communication signals allowing the reuse of allocated wireless communication signal bands for science measurements. This thesis developed a tower based SoOp instrument implementing frequencies in the P-Band and S-Band. Two field campaigns were conducted using this new instrument during the summers of 2017 and 2018 at Purdue's Agronomy Center for Research and Education.
18

Compact and Wideband MMIC Phase Shifters Using Tunable Active Inductor Loaded All-Pass Networks

Zaiden, David M. 16 November 2017 (has links)
This dissertation addresses the design of monolithically integrated phase shifters at S- and L- frequency bands using a commercially available GaAs process from Triquint. The focus of the design is to operate over a wide bandwidth with full 360° phase shift capability, 50 Ω input/output impedance match and low RMS phase and gain errors. The first version of the design is based on passive all-pass phase shifters integrated with wideband amplifiers to compensate for insertion loss. This design uses a 4-bit system to achieve the required phase shift and each bit consists of 3 sections of all-pass filters designed at separate frequencies within the 0.8 – 3 GHz band. Simulation results show a complete 360° phase shift with RMS gain error of less than 0.6 dB and RMS phase error of less than 2.5°. The system is also shown to achieve good input and output impedance matching characteristics. However, the fabricated prototype fails to perform with full functionality due to the excessive number of passive inductors in the design and the resulting mutual coupling. The mutual coupling issue could be solved by spacing out the layout to allow more separation among the inductors. Unfortunately, in the S- and L-bands, this is not an option for this research work as the fabricated design already uses the maximum allowed chip size as determined by the foundry. In addition, larger chip sizes considerably increase the cost in practical applications. To address the challenging needs of small size, wide bandwidth and low frequency applicability, the second design introduced in this dissertation proposes a novel phase shifter implementation that utilizes tunable active differential inductors within all-pass networks. The inductor tuning is used to achieve phase shifts up to 180⁰. A switchable active balanced to unbalanced transition circuit (balun) is included in front of the all-pass network to complement its phase shift capability by another 180°. In addition, the all-pass network is followed by a variable gain amplifier (VGA) to correct for gain variations among the phase shifting states and act as an output buffer. Although active inductors have been previously used in the design of various components, to the best of our knowledge, this is the first time that they have been used in an all-pass phase shifter. The approach is demonstrated with an on-chip design and implementation exhibiting wideband performance for S and L band applications by utilizing the 0.5 µm TriQuint pHEMT GaAs MMIC process. Specifically, the presented phase shifter exhibits 1 × 3.95 mm2 die area and operates within the 1.5 GHz to 3 GHz band (i.e. 2:1 bandwidth) with 10 dB gain, less than 1.5 dB RMS gain error and less than 9° RMS phase error. Comparison with the state-of-the-art MMIC phase shifters operating in S and L bands demonstrates that the presented phase shifter exhibits a remarkable bandwidth performance from a very compact footprint with low power consumption. Consequently, it presents an important alternative for implementation of wideband phase shifters where all-passive implementations will consume expensive die real estate.
19

Konstruktion av testsändare inom S-bandet / Design of S-band Test Transmitter

Siewers, Mari January 2010 (has links)
<p>Detta examensarbete har som syfte att konstruera en prototyp av en testsändare inom Sbandet,2.2 – 2.4 GHz. Arbetet innefattar konstruktion och utveckling av hårdvara och kodför testsändaren, samt tester och optimering av den framtagna prototypen.Koden designades för en FPGA i Quartus II med VHDL. I FPGA:n hanteraskommunikationen mellan användaren och hårdvaran. Designen av mönsterkortet gjordes iprogrammet Altium Designer. Det resulterade i ett kretskort i glasfiber med två lager ochytmonterade komponenter som handlöddes. Huvudkretsarna i hårdvaran är en FPGA, enfrekvensmixer, en lokaloscillator och två olika förstärkare. Lokaloscillatorn genererarbärfrekvensen medans FPGA:n modulerar indata och omvandlar det till datafrekvenser.Mixern blandar bärfrekvensen med data via amplitudmodulering och ger ut en RF-signalsom förstärks innan den sänds ut.Resultatet efter optimering är att testsändaren genererar en ren bärfrekvens inomS-bandet och kompenserar väl för modulationsfel vid generering av RF-signalen. Denöverför data som vid test kan avläsas och valideras av en demoduleringsapparat förflygdata.</p>
20

Konstruktion av testsändare inom S-bandet / Design of S-band Test Transmitter

Siewers, Mari January 2010 (has links)
Detta examensarbete har som syfte att konstruera en prototyp av en testsändare inom Sbandet,2.2 – 2.4 GHz. Arbetet innefattar konstruktion och utveckling av hårdvara och kodför testsändaren, samt tester och optimering av den framtagna prototypen.Koden designades för en FPGA i Quartus II med VHDL. I FPGA:n hanteraskommunikationen mellan användaren och hårdvaran. Designen av mönsterkortet gjordes iprogrammet Altium Designer. Det resulterade i ett kretskort i glasfiber med två lager ochytmonterade komponenter som handlöddes. Huvudkretsarna i hårdvaran är en FPGA, enfrekvensmixer, en lokaloscillator och två olika förstärkare. Lokaloscillatorn genererarbärfrekvensen medans FPGA:n modulerar indata och omvandlar det till datafrekvenser.Mixern blandar bärfrekvensen med data via amplitudmodulering och ger ut en RF-signalsom förstärks innan den sänds ut.Resultatet efter optimering är att testsändaren genererar en ren bärfrekvens inomS-bandet och kompenserar väl för modulationsfel vid generering av RF-signalen. Denöverför data som vid test kan avläsas och valideras av en demoduleringsapparat förflygdata.

Page generated in 0.0389 seconds